(Adapted from Applicant's Abstract) The Myocyte and Morphology Core supports the objectives of the program project. All four projects make use of this core in their research for either transgenic mouse or rat hearts during different phases of congestive heart failure. The Myocyte part of this core has been constructed to met the increasing demands of experiments to isolate single cardiomyocytes from mice or rats and to do mechanics and microfluorimetric experiments on these intact cells. The Morphology part of this core is able to perform all anatomical studies of the organs and cells generated by Projects 1-4. The Myocyte and Morphology Core. 1) provides enzymatically isolated cardiac myocytes from neonatal and adult, mouse and rat hearts, 2) provides technical support in single cell mechanical and microfluorimetric experiments. 3) maintains facilities used for myocyte isolation and intact cell mechanics and microfluorimetric experiments. 4) evaluates morphology on transgenic mice and failing hearts with conventional light, fluorescent, confocal and electron failing hearts with conventional light, fluorescent, confocal and electron microscopy complimented by histochemistry, immunochemistry and in situ hybridization as necessary. 5) advises about statistical sampling and quantitative Morphometric analysis of images obtained.